Troy Matteson kept up his furious pace with a five-under 66 to lead by three from three-time defending champion Steve Stricker going into the final round of the John Deere Classic.
Following rounds of 10 under and three under, Matteson was stellar again, carding seven birdies against a couple of bogies to sit 18 under overall.
Stricker, looking for his fourth straight John Deere title, matched him shot for shot - although he left it late.
Two under through 13, Stricker had four consecutive birdies from 14 before bogeying the 18th, where Matteson also dropped a shot.
Winning again would enable Stricker to fly to The Open next week having equalled the feat achieved by Young Tom Morris at Prestwick in 1968-72 and also by Walter Hagen at the USPGA Championship, Gene Sarazen in the Miami Open and Woods at both Bay Hill and the Buick Invitational.
Matteson was under no illusions as to who will have popular support on the final day.
"You always want to be ahead rather than behind," he said. "Every stroke you can gain is good.
"Steve is a great guy. He's the kind of guy that personifies what we're looking for on the Tour. He's the kind of guy you can tell your kids to use as a role model.
"He's just a really good guy. He's a good guy to have at the top of the leaderboard at any tournament, especially John Deere because of what he's done here in the past.
"I think it'll be really fun to play with him.
"I'm pretty used to if I'm playing in the last couple of groups, I'm not the guy people root for, so I think that it'll be pretty normal for me."
Stricker said the key for his playing partner would be dealing with the pressure.
"I've been in this position Troy's in, and it's a difficult position because you have the expectations that you should go out and win," he said.
"It's still very hard, because guys behind you are going for broke and they can be a little bit more aggressive and take a shot at pins.
"That's what he's going to have to deal with tomorrow."
Stricker finished the day with 10 players within three shots of him, notably local favourite Zach Johnson, just one stroke back.
Like the two men ahead of him, Johnson carded seven birdies and two bogeys, leaving him alongside Brian Harman on 14 under.
Billy Hurley III, who had a best-of-the-day seven-under 64, 2006 champion John Senden and JJ Henry were 13 under, while England's Gary Christian was in a group of five players on 12 under.
Collated third round scores & totals in the USPGA Tour John Deere Classic, The TPC at Deere Run, Silvis, Illinois, United States of America
(USA unless stated, par 71):
195 Troy Matteson 61 68 66
198 Steve Stricker 65 67 66
199 Zach Johnson 68 65 66, Brian Harman 65 65 69
200 Billy Hurley III 68 68 64, J J Henry 67 64 69, John Senden (Aus) 69 64 67
201 Chris Di Marco 66 67 68, Bobby Gates 66 68 67, Gary Christian (Eng) 65 66 70, Scott Piercy 65 69 67, Jamie Lovemark 71 66 64
202 Ricky Barnes 64 67 71, Jeff Maggert 68 62 72, Scott Brown 70 66 66, Robert Garrigus 65 66 71, Stuart Appleby (Aus) 66 69 67, Ryan Moore 67 69 66
203 Brendon De Jonge 68 68 67, Seung-yul Noh (Kor) 68 69 66, Erik Compton 68 69 66, Lee Janzen 67 65 71, Billy Horschel 70 68 65, Tim Clark (Rsa) 67 68 68, Tommy Biershenk 66 66 71, Y.E. Yang (Kor) 68 65 70
204 Chris Kirk 68 68 68, Luke Guthrie 65 68 71, John Merrick 67 67 70, Chris Couch 67 67 70, Chad Campbell 68 70 66, Duffy Waldorf 66 69 69, K J Choi (Kor) 65 72 67, Matthew Every 71 65 68, Tom Gillis 66 69 69, Jonathan Byrd 72 66 66, Tommy Gainey 69 66 69
205 Nick Watney 68 68 69, Jimmy Walker 66 71 68, Kevin Streelman 68 69 68
206 Spencer Levin 66 71 69, Scott Dunlap 70 68 68, Martin Flores 67 67 72, Kyle Stanley 68 69 69, Jeff Overton 69 68 69, Steve Wheatcroft 67 70 69, Alex Cejka (Ger) 67 68 71, Mark Wilson 69 68 69, Blake Adams 71 67 68, Ben Crane 66 67 73, Camilo Villegas (Col) 71 66 69
207 Jerry Kelly 69 69 69, Rory Sabbatini (Rsa) 67 68 72, Ted Potter, Jr. 67 66 74, Randall Hutchison 68 68 71, Mathias Gronberg (Swe) 69 69 69, Matt Bettencourt 68 70 69, Chez Reavie 67 70 70, Josh Teater 69 69 69
208 Nathan Green (Aus) 67 69 72, Chris Stroud 68 70 70, Bill Lunde 66 72 70, Vaughn Taylor 72 66 70, Dicky Pride 67 68 73, Danny Lee (Nzl) 70 68 70, Carl Pettersson (Swe) 68 69 71, J.J Killeen 68 68 72
209 Chris Riley 68 70 71, Roland Thatcher 69 68 72, Mark Anderson 69 67 73, Jordan Spieth 70 67 72
210 Charley Hoffman 68 68 74, Hunter Haas 67 69 74
211 Alexandre Rocha (Bra) 70 68 73, Kevin Chappell 70 68 73
212 Marco Dawson 70 68 74
213 Bud Cauley 69 69 75
